Internal combustion engine



FIG. 1 is a left/front perspective view of an internal combustion engineshowing my new design.

FIG. 2 is a front view thereof.

FIG. 3 is a rear view thereof.

FIG. 4 is a right side view thereof.

FIG. 5 is a left side view thereof.

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

The ornamental design for an internal combustion engine, as shown anddescribed.